<PRE><B>Question 661470</B>
joe traveled 40 mph to a hotel ;
 taking the same route back he drove 10 mph back ;
 what was the average speed
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To hospital DATA:
rate = 40 mph ; distance = x miles ; time = x/40 hrs.
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To home DATA:
rate = 10 mph ; distance = x miles ; time = x/10 hrs.
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Average speed = total distance/total time = (2x)/[(x/40)+(x/10)]
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= (2x)/[(10x+40x)/(400)]
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= (2x)/[(50x)/400]
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= (800x/50x]
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= 16 mph
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Cheers,
Stan H.
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